Underwater well completion method and apparatus

ABSTRACT

Extended casing method and apparatus for completing an underwater well whereby complete and continuous pressure control is maintained at the surface drilling platform. A conductor casing is installed in the floor of a body of water with a casing head and riser attached near the floor. Other casing is installed and supported at the water floor by hanger heads and having other risers extending upwardly therefrom. Pressure control equipment is installed at the upper end of one of the risers. A tubing hanger and tubing, designed to pass through the pressure control equipment and riser to which it is attached is lowered into the innermost hanger-head and remotely latched thereto. The tubing is plugged, the riser and control equipment removed and a Christmas tree assembly attached to the wellhead in fluidtight flow communication with the tubing string.

United States Patent 3,847,215

Herd Nov. 12, 1974 1 UNDERWATER WELL COMPLETION 3,459,259 8/1969 Matthews tea .5

METHOD AND APPARATUS [75] Inventor: David P. Herd, Houston, Tex.

[73] Assignee: McEvoy Oilfield Equipment Co., Pittsburgh, Pa.

[22] Filed: Aug. 13, 1973 [21] Appl. No.: 387,915

Related U.S. Application Data [60] Division of Ser. No. 103,839. Jan. 4, 1971, Pat. Nov

3,800,869, which is a continuation oi Ser. No.

792,912, Ian. 22, 1969, abandoned.

[52] U.S. CI. l66/.6, 166/315 [51] Int. Cl E2lb 33/035 {58] Field of Search 166/.5, .6, 313, 315, 89;

[56] References Cited UNITED STATES PATENTS 1.849.374 3/1932 McEvoy et a1 2,974,505 6/1957 Ail 5T1: 166/86 3,097,695 7/1963 Le Rouax 166/75 3,098,524 7/1963 Brown 166/313 3,099,317 7/1963 Todd 166/.6 3,421,580 l/l969 Fowler et al... 166/85 3,451,481 6/1969 Lanmon 166/313 OTHER PUBLICATIONS Marine Completions Cameron Marine Systems Cameron Iron Works Inc., 1966.

Primary Eraminer-James A. Leppink [57] ABSTRACT Extended casing method and apparatus for completing an underwater well whereby complete and continuous pressure control is maintained at the surface drilling platform. A conductor casing is installed in the floor of a body of water with a casing head and riser attached near the floor. Other casing is installed and supported at the water floor by hanger heads and having other risers extending upwardly therefrom. Pressure control equipment is installed at the upper end of one of the risers. A tubing hanger and tubing, designed to pass through the pressure control equipment and riser to which itis attached is lowered into the innermost hanger-head and remotely latched thereto. The tubing is plugged, the riser and control equipment removed and a Christmas tree assembly attached to the wellhead in fluidtight flow communication with the tubing string.

32 Claims, 14 Drawing Figures PATENTEUNUV 12 1974 sum 01 or 11 PMEN IFEHP m we I974 saw on HF 11 t Iiiii I'l I'l PATENTEDmvmsM sum 0601 11 .847.215

PATENTEDnnv 12 1974 I 3 847 215 I SHEET T10 0F 11 UNDERWATER WELL COMPLETION METHOD AND APPARATUS This is a division of application Ser. No. 103,839 filed Jan. 4, 1971, now U.S. Pat. No. 3,800,869 which is a continuation of application Ser. No. 792,912 filed Jan. 22, 1969, now abandoned.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention concerns underwater drilling of oil and gas wells. Specifically, it pertains to methods and apparatus used in underwater extended casing operations.

2. Description of the Prior Art Increased activity in offshore drilling has resulted in a continuous search for better methods and apparatus in this area. To cope with the unique problems associated with'underwater drilling various extended casing methods have been developed. Basically, extended casing methods have a well conductor anchored to the sea floor which provides support for a special underwater wellhead. The wellhead, in turn, supports a multiple number of casing strings and their respective casing hangers. The drilling platform is thus relieved of much of the structural support responsibilities of other methods. After drilling is completed, the well may be permanently abandoned, temporarily abandoned or immediately completed. For any of these options, the completion equipment may be installed at the sea floor, leaving the drilling platform free for relocation and freeing the underwater wellhead from the hazards of ocean going traffic and structural support problems. One such extended casing method is fully described in copending U.S. Pat. application Ser. No. 572,599.

In the extended casing methods of the prior art, one or more intermediate casing strings, in addition to the conductor casing and the innermost production casing string, are usually supported in the wellhead. Casing extensions or risers are attached to these strings as they are lowered into place and landed. The extensions are connected at the surface to a blowout preventer for pressure control and also serve as a return for cement circulation. Inthe past it has been necessary to remove all casing extensions, except possibly the outer conductor riser, for installation of the tubing hanger and tubing strings. Since blowout preventers of the conductor riser size are not usually available, the well hole has no pressure control during the installation of the tubing strings unless a bridge plug is installed in the production casing string. If a bridge plug is installed it must be removed by drilling or otherwise. These operations require additional equipment, time and, consequently, expenses. Other time delays are encountered in removing each casing extension since blowout preventers must be disconnected and other size preventers connected to the next casing string extension.

Some methods have utilized underwater blowout preventers installed near the underwater wellhead. However, such preventers are very expensive and more complex to operate though than the conventional above water type.

SUMMARY OF THE INVENTION The present invention concerns a method of completing an underwater well comprising the steps of: locating drilling means at an underwater well site; installing conductor casing in the floor of a body of water with a casing head and riser attached thereto at a point near the floor, the conductor riser extending upwardly to the drilling means; drilling holes for, suspending within the conductor casing and cementing in place other casing, each of the other casing being suspended by hanger means above which other risers, extending upwardly to the drilling means, are connected; attaching blowout pressure control equipment to the top of at least one of the other risers; running a tubing hanger and at least one tubing string, through the control equipment and the riser to which it is attached, into the innermost casing; suspending and latching the tubing hanger and tubing string in the innermost hanger means; and removing the pressure control equipment and the other risers.

This method provides complete and continuous pressure control throughout completion by providing apparatus whereby the tubing hanger and tubing string may be lowered through blowout preventers and a riser to their support positions. After latching the tubing hanger and tubing string in place the tubing is plugged and the riser and pressure control equipment is removed for installation of the Christmas tree assembly.

become apparent from the description which follows when taken in conjunction with the drawing in which:

FIGS. 1 through 6 are step by step sectional elevation views of an underwater well showing a method and apparatus for completing a dual tubing string well according to a preferred embodiment of the invention, and

FIGS. 7 through 10 are step by step sectional elevation views of an underwater well showing a method and apparatus for tubingless completion of a well according to a preferred embodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is an extended casing completion system for use when drilling from a bottom supported rig with blowout prevention control equipment at the surface. Several options on the method of completion are available, including:

1. Easy permanent abandonment, 2. Temporary abandonment, 3. Completion by extension of casing, risers to a platform, 4. Casing-tubing sub-surface completion with optional diver support or fully remote operation, and

5. Tubingless sub-surface completion with optional diver support or fully remote operation. The apparatus of the present invention permits installation of one or more tubing strings through blowout prevention control equipment and extended risers, eliminating the necessity of removing the risers and blowout preventers when preparing the well for completion. Because all operations are conducted through the risers and blowout preventers, well pressure control is continuous and remote guidance systems are not necessary when temporarily abandoning the well or preparing it for completion. A guide base is not installed until a decision is made to complete the well. This allows a selection at that time of either fully remote Christmas tree installation or diver support Christmas tree installation.

Referring first to FIGS. 1 through 6, a step by step description of casing-tubing sub-surface completion, according to a preferred embodiment of the invention, will be given. The system described will be a 30 inches X 16 inches X it inches X 7 inches casing program with two 2 it; inches tubing strings. However, it is to be understood that the size and number of casing and tubing may vary without departing from the principles of the invention.

First, a 30 inch conductor casing 10, casing head 11, and conductor riser 12 are lowered from the drilling platform (not shown) and driven or jetted into the sea floor 1 until casing head 11 rests near the floor. lf bottom conditions require it, a hole may be drilled for conductor casing 10. Casing head 11 is provided with an upwardly facing stop shoulder 13 for locating the surface casing.

Riser 12 is connected to casing head 11 by an easily disengageable connection 14. One type of easily disengageable joint is shown in FIG. 1A. This type of joint, which we refer to as a breech block joint, reduces drilling costs by eliminating on-site welding, permitting easy recovery of easing risers and reducing rig time during making, running and recovering casing risers. The joint comprises a female member and a male member 30. Segmented threads 21 of a square nonlead profile spaced 30 apart are milled in the female member for engagement with corresponding segmented threads 31 on the male member. Smooth milled out areas 22, 32 are provided between the thread segments 21, 31. For descriptive purposes the thread segments 21, 31 are referred to as lands and milled out areas 22, 32 as grooves. Engagement is accomplished by inserting the lands of the male member 30 in the grooves of the female member 20, then rotating the male member 30 thirty degrees in either direction until the lands of each member are in full engagement. A positional stop 33 on the male member cooperates with lugs 35 around the female member to limit rotation to thirty degrees. A pivotable anti-rotation latch 34 may be provided to engage the opposite side of lugs 35 preventing disengagement of the joint.

After the 30 inch conductor casing is set, a hole is drilled for 16 inch surface casing 40, which is lowered into place with surface casing head 41, back-off joint 42 and surface casing riser 43 attached thereto. Backoff joint 42 and head 41 may be connected by a breech block joint 46 similar to that shown in FIG. 1A. Landing lugs 44 are provided on surface casing head 41 cooperating with stop shoulder 13 to locate surface casing 40. The surface casing 40 is then cemented in place. The remaining strings will be supported by the cement around surface casing 40. Casing head 41 is provided with internal annular recesses to receive hanging latches for the next string.

Next a hole is drilled for the 10% inch intermediate casin g stringSO which is lowered into the hole attached to hanger-head 51, back-off joint 52, and riser 53 and cemented in place. Hanger-head 51 and back-off joint 52 are connected with another breech block connection 54. Hanger-head 51 is provided with spring biased latches 55 which support the casing string 50 within the well. As the latches 55 engage recesses 45, a locking rib 56 on the hanger-head body locks them into positive engagement. Hanger-head 51 may be provided with internal circulation ducts 57 or the latches may be fluted for cement circulation. Internal latch recess 58 and circulation ducts 59 may be provided for ducting around the next hanger-head. Blowout prevention control equipment is attached to the top of riser 53 at the drilling platform (not shown).

Next the hole for production casing string 60 is drilled and the production string is landed and cemented in place attached to hanger-head 61, back-off joint 62 and riser 63. Production string hanger-head 61 is similar to hanger-head 51 having spring latches 65 a locking rib 66 and if necessary flow ducts 67. However, it has no internal latch recesses and it is connected to back-off joint 62 by a left hand thread connection 64 rather than a breech block joint. Immediately above the connection 64 two internal tubing hanger hold down recesses 68 are cut. An external key 69 provides orientation for a subsequently installed tubing hanger. Therefore, the production string 60 must be properly oriented while running in place.

The aforementioned drilling is done through the blowout prevention equipment at the drilling platform. At this stage of the drilling, the wellhead equipment would be as shown in FIG. 1. At this time the production string riser 63 is removed by rotating the riser 63 and back-off joint 62 to the right.

Referring specifically now to FIG. 2, an orientation sleeve 70 connected by a .1 slot arrangement 76 to running tool 71 and running string 72 is run through 10 /4 inch riser 53. A longitudinal slot at the base of sleeve 70 engages hanger-head key 69 and the sleeve comes to rest against hanger-head shoulder 73. An orientation bushing 74 is affixed to the interior of sleeve 70 for automatic guidance of a tubing hanger which is to be installed. It has a dual 180 ramp 75 and a vertical slot 76 communicating with the ramp at its lowermost intersection. Tool 71 is then disconnected from orientation sleeve 70 and removed.

Referring now to FIG. 3, a tubing hanger 80, tubing 90, 91 and annular access nipple 92 are installed along with tubing running tool 93. Tubing hanger 80 is provided with three vertical bores 81, 82 (one not shown) communicating with annular access nipple 92 and tubing strings 90, 91. Long tubing handling string 94 is connected to hanger 80 by a handling nipple (not shown) similar to handling nipple 95 connected to short string handling string 96. Both nipples pass through running tool 93. However, nipple 95 is screwed into a landing nipple 96 whereas the long string handling nipple is screwed directly in hanger 80. Both tubing strings 90, 91 are lowered together. However, short string 91 is displaced upwardly a slight amount from the position shown in FIG. 3.

Hanger 80 is provided with a longitudinal key 83 which rides on orientation bushing ramp 75 until it engages orientation slot 76 orienting the tubing hanger 80. The tubing hanger comes to rest on the upper shoulder 85 hanger-head 61. A hold down latch 86 and locking sleeve 87 are mounted in a skirt portion of hanger 80 near its base. In the running position the latch 86 is retracted and locking sleeve 87 is held up against the body of hanger 80 by engagement with landing nipple 95. When the hanger 80 is landed, short tubing string 91 and landing nipple 96 are allowed to move downwardly to the position shown in FIG. 3, where it is supported by shoulder 88, causing locking sleeve 87 to force hold down latch 86 into engagement with hanger-head hold down recesses 68. Up to this point handling nipple 96 and landing nipple 96 are fully made up so that the upper edge of landing nipple 96 is abutting downwardly facing shoulder 97 on handling nipple 95. By rotating handling nipple 95 to the right these shoulders are separated allowing a snap ring 89 in hanger 80 to spring out engaging the upper edge of landing nipple 96 and holding the short tubing string 91 down. At this point all wellhead components appear as shown in FIG. 3.

Next the tubing hanger seals would be tested by pressurizing through short tubing string 91. Pressure would then be applied below the tubing hanger 80 and through annular access nipple 92 and tubing 90. Testing tool 93 is provided with a vertical port 98 and a horizontal port 99 which communicates with long tubing string 90 through a port in the handling nipple (not shown) attached to handling string 94. Should any of the seals around hanger 80 and landing nipple 96 leak it will be detected in riser 53.

Next, the downhole tubing packer is set, usually by hydraulic means, a back pressure valve is installed in long string 90 and the packer pressure tested. Pressure is applied through short string 91. If the packer leaks the test fluid passes through annular access nipple 92 and through test tool ports 98, 99 into handling string 94 for detection.

If all tests are positive, the tubing handling strings 94, 96, their respective handling nipples, and test tool 93 are removed from the hole by rotating the handling strings to the right. The tubing strings 90, 91 and annulus access nipple 92 are plugged. It will be noticed that throughout running and setting of the tubing hanger and tubing strings complete pressure control is maintained at the surface by blowout prevention equipment connected to "3 1 inch riser 53.

Next, the pressure control equipment, 10 inch riser 53 and 16 inch riser 43 are removed by 30 rotation to the right for disengagement of breech block connections 54 and 46. At this stage, the wellhead will appear as shown in FIG. 4 with conductor extension 12 being I the only remaining riser.

Referring now to FIG. 5, a tubular Christmas tree adapter 100 is run on drill pipe 120 using a combination running testing tool 130. The external midportion of adapter 100 is provided with the male part of a breech block connection 101 for engagement with the female part of the connection 101 in the 10 34. inch head 51. Rotatably connected by ball bearings 102 to the lower part of adapter 100 is an annular packoff assembly comprising aresilient seal member 104 sandwiched between upper and lower retainer members 103, 105. Lower retainer 105 is stopped against hangerhead shoulder 106 and as the breech block connection 101 is engaged upper retainer ring 104 presses against seal member 104 causing it to sealingly engage the walls of hanger-heads 51 and 61. A port 131 connects the bore 132 of tool 130 with the annular space between adapter 100 and tubing hanger 80. This space is sealed at 133, 134 by O-rings, allowing adapter seals 104, 108, 109 and tubing hanger seals 110 to be tested.

Christmas tree adapter 100 has an upper flange member 111 and internal connection threads 112 to which tool is connected. Christmas tree adapter 100 also has stop lugs 113 which cooperate with stop lugs 114 on the top of hanger-head 51 when the breech-block connection is made to stop rotation at full engagement. To prevent disengagement, a locking ring 115 with depending lugs 116, is mounted around adapter 100 and held upwardly thereon as shown by radial pins 117 which ride in an L slot in sleeve skirt 136 of tool 130. A shear pin 137 is sheared on further right hand rotation of tool 130. This allows skirt 136 to rotate to a position where pins 117 drop out of the L slot allowing the locking ring 115 to drop downwardly so that its lugs 116 fall between the back of adapter lugs 113 and the next closest hanger-head lug 114. This prevents rotation of adapter 100 in either direction thus locking it in position. Further rotation of tool 130, to the right, releases it for removal from the well.

If it is decided to temporarily abandon the well, rather than immediately complete it, a corrosion cap (not shown) may be run on drill pipe using a J type running tool. It would be connected to the internal threads 112 of tubing head adapter 100. The corrosion cap could be provided with a port for spotting oil within the wellhead to prevent corrosion. This port would, of course, be plugged after the oil was injected. After installation of the corrosion cap, conductor riser 12 would be removed by rotating 30 to the right. A corrosion cap top could be installed by a diver and the well could be temporarily abandoned.

Alternatively, if it is desired to immediately complete the well, rather than install a corrosion cap, the Christmas tree would be installed. To do this, conductor riser 12 would be removed. Now referring also to FIG. 6, a small guide base 140 with two guide posts 141 would be clamped around the lower part of adapter 100 or hanger-head 51 by a diver. The guide base would be oriented by a tool with two pins adapted to engage tubing hanger receiving pockets 118, 119.

Next, Christmas tree would be lowered to the wellhead. It would be provided with guide arms 151 and bell bottom sleeves 152 which would engage guide posts 141 to assist a diver in installing the tree 150. The base of tree 150 carries two long nipples 153, 154 which sealingly engage the corresponding receiving sockets 118, 119 in hanger 80. The base of tree 150 would come to rest against the upper face of adapter 100. An annular seal ring 155 would be provided at the joint. The tree 150 is then clamped to Christmas tree adapter 100 by a standard type clamp 160. A remote hydraulic connector could be used as an option eliminating the need for a diver to torque up clamp bolts. Thus, as shown in FIG. 6, the well is ready for production.

Should it be necessary at a future date to perform workover operations, tubing strings 90, 91 would be plugged and the Christmas tree 150 removed. Then a workover riser with a built in orientation sleeve and bushing similar to sleeve 70 and bushing 74 in FIGS. 2 and 3 would be attached to tree adapter 100. The orientation bushing would have a slot to engage key 83 of tubing hanger 80. In this manner, after the tubing hanger 80 is re-installed, following workover operations, it is landed in the same position as it was before workover operations.

If a tubingless sub-surface completion is desired, instead of a casing-tubing sub-surface completion, a somewhat different procedure is followed. However, with reference to FIG. 7, the first steps are the same as in the casing-tubing sub-surface completion just described. A 30 inch conductor casing 210, casing head 211, and conductor riser 212 connected by breechblock joint 214 are installed. A 16 inch surface casing 240, casing head 241, back-off joint 242, and riser 243 are installed. Next, the inch casing string 250, hanger-head 251, back-off joint 252, and riser 253 are installed as in the conventional completion.

There is a slight difference in hanger-head 251 and back-off joint 252. Hanger-head 251 is provided with an internal vertical slot 259 immediately above the hanging recesses 258. Orientation in this method will be obtained by orienting the 10 hanger-head rather than the 7 inch hanger-head in the aforedescribed casing-tubing sub-surface completion. Backoff joint 252 is provided with an orientating bushing 260 which has a double ramp orienting slot 261 cut on a 45 angle. A vertical slot 262 is cut at the bottom or ramp 261 for alignment with hanger head slot 259. A hanger-head and back-off joint equipped with the modifications of hanger-head 251 and back-off joint 252 could be used with the casing-tubing sub-surface completion previously described, providing an option, at this point, of either casing-tubing completion or tubingless completion.

Blowout prevention equipment (not shown) is attached at the upper end of riser 253 at the drilling platform. Running of tubing will be performed through this blowout prevention equipment so that full pressure control is maintained at all times as in the previously described method.

In the next step, two strings of tubing 270, 271 are clamped together and run in the well tied by shear pins 273 to a tubing hanger assembly 280. Tubing hanger 280 is provided with outwardly biased hanging latches 281 and inwardly biased tubing latches 282 around openings 284, 285 through which tubing strings 270, 271 pass. An offset opening (not shown) through the hanger 280 provides access to the annulus between the tubing string 270, 271 and 10 54 inch casing 250. This allows both cementing circulation and limited gas lift production.

Also provided on hanger 280 is an external spring loaded dog 290. Referring also to FIG. 7A dog 290 is beveled at the top 291 and bottom 292 so that it is cammed inwardly by any horizontal shoulder it encounters as the hanger is lowered into the well. However, looking at the face of dog 290, its bottom 292 is V shaped providing 45 angle edges 293, 294. If these angle edges 293, 294 encounter a matching 45 angle shoulder such as orienting ramp 261, the dog 290 will not be cammed inwardly but will ride down the ramp causing the tubing hanger 280 to rotate therewith. Thus, as the tubing strings 270, 271 and hanger 280 are lowered into the well, dog 290 engages ramp slot 261 rotating the hanger 280 until dog 290 falls through vertical slot 262 and into slot 259 as shown. Latches 281 engage hanging recesses 258 in a proper orientation.

Attached to the upper end of tubing strings 270, 271 are tubing hanging nipples 27 5, 276 which are provided with external hanging grooves 277, 278. One of the nipples, in this case 275, is longer than the other for reasons to be described subsequently. Running tools 286, 287 connect the hanging nipples 275, 276 to running strings 296, 297.

After the tubing hanger 280 is in place as shown in FIG. 7, the weight of tubing 270, 271 shears pins 273.

Both strings 270, 271 are then run to bottom and tubing latches'282 engage the latch grooves 277, 278 in hanging nipples 275, 276, supporting the tubing strings as shown in FIG. 8. Both strings can then be cemented and handling strings 296, 297 and running tools 286, 287 removed by rotation to the right. At this stage of completion the wellhead equipment appears as in FIG.

If for any reason tubing strings 270, 271 should become stuck after tubing hanger 280 is latched in, and cannot be freed, both strings would be cemented in.

Then a standard outside tubing cutter would be run over one of the tubing strings. The cutter would be modified slightly to support tubing slips at its bottom. These tubing slips (not shown) would be lowered to engage tapered receiving bowls 288, 289 in the top of the hanger 280. The slips would be set and then the tubing string would be cut off at a distance from hanger 280 equal to the height of hanging nipples 275, 276, one longer than the other. After one tubing is set and cut the same procedure would be followed for the other tubing string.

Next, tubing strings 270, 271 are plugged and risers 253 and 243 are removed by 30 rotational disengagement of breech-block connections 246, 254 as in the casing-tubing sub-surface completion previously discussed. This leaves only the 30 inch riser 212.

As now shown in FIG. 9, a Christmas tree adapter 300, similar to the adapter (FIGS. 5 and 6), is lowered through riser 212 on drill pipe 320 and combination running and testing tool 330. The external midportion of adapter 300 is provided with the male part of breech-block connection 301 for engagement with head 251. Rotatably connected by ball bearings 302, at the lower part of adapter 300, is annular packoff assembly 303. Assembly 303 differs from the casingtubing sub-surface completion apparatus in that it is designed to also packoff around hanging nipples 275, 276 as well as against head 251. The lower retaining ring 304 of packoff assembly 303 is provided with an offset frusto-conical surface, the axis of which coincides with the axis of landing nipple 275. Thus, if the packoff assembly is not properly oriented as tubing head adapter 300 is lowered into place, the frusto-conical surface 305 contacts one of the tubing nipples, and is cammed around to the proper orientation. Nipple 275 is longer than nipple 276 to prevent the possibility of both nipples contacting surface 305 at the same time should assembly 300 be exactly ninety degrees out of proper orientation. Packoff assembly 300 also has an annular access port 306.

Running tool 330 seals on the inside diameter of adapter 300 at 307 and on the outside diameter of hanging nipples 275, 276 at 308, 309. Internal porting 310 within the tool 330 permits pressure testing of the packoff assembly 303.

Christmas tree adapter 300 has an upper flange member 311 and internal connection threads 312 to which tool 330 is connected. The adapter 300 also has stop lugs 313 which cooperate with hanger-head stop lugs 314 to limit stop rotation at full engagement as explained with reference to FIG. 5 in the casing-tubing sub-surface completion method previously described herein. Also provided is a lock ring 315 held first in an upward position by sleeve skirt 336 of the tool 330. After shearing of pin 337 right hand rotation of tool 330 allows pins 317 to drop out of L slots 335 in sleeve 336 allowing its lugs 316 to drop between the back of adapter lugs 313 and the next closest hangerhead lugs 314, locking the adapter in its fully engaged position. Further rotation of tool 330 frees it for retrieval from the well.

The well can then be temporarily abandoned as explained in the casing-tubing sub-surface method previously described or it can be completed for production. If it is to be completed for production, at this point, conductor riser 212 is disconnected from conductor head 211 by 30 rotation and removed.

Now referring to FIG. 10, a spool piece 350, and Christmas tree 360 is guided into place and attached to adapter flange 311 by standard type diver assist clamp 351. Spool piece 350 may be lowered by itself first with Christmas tree 360 being lowered afterward. Alternatively, Christmas tree 360 may be assembled with spool piece 350 by clamp 361, then lowered together into place for attachment to adapter 300. Spool piece 350 is provided with nipples 352, 353 which stab and seal over hanging nipples 275, 276. It is also provided with a side opening outlet 354 and bore 355 communicating with port 306 and tubing-casing annulus below hanger 280 through a port (not shown) in hanger 280. A valve removal plug 356 allows for future installation of a side outlet valve. Christmas tree 360 is provided with short nipples 362, 363 which sealingly engage pockets provided for this purpose in spool piece 350. Nipples 362, 363, 352, 353, 275, 276 and spool bores 357, 358 provide unobstructed full opening into tubing strings 270, 271.

The foregoing methods and apparatus for completing an underwater well for both the casing-tubing sub-sea completion or tubingless completion offer definite advantages in both speed and safety. Complete pressure control at the drilling platform is maintained at all times and the apparatus used permits fast connection and disconnection for reduction of expensive rig time.

We claim:

1. A method of suspending at least one string of pipe in a well with only one trip into the well comprising the following steps:

running a well pipe hanger assembly which suspends the pipe string into the well on at least two handling strings;

aligning the well pipe hanger assembly in a predetermined position within the well;

landing the well pipe hanger assembly within the well;

locking down the well pipe hanger assembly within the well;

testing the seals in the well pipe hanger assembly by pressurizing the handling strings,

testing the integrity of the packer in the pipe string by monitoring one of the handling strings; and removing the handling strings.

2. An underwater well pipe hanger assembly for suspending at least one string of pipe having a packer in a well comprising:

a hanger body;

support means for supporting said hanger body within the well;

securement means for securing said hanger body within the well;

locking means for locking said securement means in a secured position;

actuator means for moving said locking means to its locking position; alignment means for aligning said hanger assembly;

suspension means on said hanger body for suspending the string of pipe therefrom;

seal means between said hanger body and said suspension means; and

testing means on said hanger body extending to the surface and lowered with said hanger body into the well for testing the integrity of said seal means and the packer.

3. A pipe hanger assembly according to claim 2 wherein said hanger body is adapted for releasable con nection to a well too], and wherein said actuator means includes means for releasably and rotatably connecting said actuator means to the well tool, and wherein said locking means is movable into its locking position by longitudinal force applied to said actuator means by the well too].

4. A pipe hanger assembly according to claim 3 wherein rotation of said well tool releases its connection to said hanger body.

5. A pipe hanger assembly according to claim 2 and including a reference member disposed in a predetermined direction with the well wherein said alignment means comprises an alignment key protruding from said assembly, said alignment key cooperating with said reference member to cause rotation of said hanger assembly until said assembly is aligned within the well in a predetermined direction, and then to preclude further rotation of said alignment key and said hanger body.

6. A pipe hanger assembly according to claim 5 wherein said reference member has a helically generated upwardly facing surface cooperable with said alignment key causing said hanger assembly to become aligned within the well in a predetermined direction.

7. An assembly according to claim 2 wherein said testing means includes at least two conduits extending to the surface;

one of said conduits being in fluid tight communication with the pipe string; and

means providing communication between the space below said hanger body and said second conduit.

8. An assembly according to claim 7 wherein said conduits lower said hanger body into the well.

9. A well pipe hanger assembly for suspending at least one string of pipe having a packer in a well comprising:

a hanger body having at least one axial bore therethrough;

support means for supporting said hanger body within such well;

securement means for securing said hanger body within such well;

locking means for locking said securement means in a secured position;

actuator means for moving said locking means to its locking position;

alignment means for aligning the hanger assembly;

suspension means on said hanger body for suspending the string of pipe therefrom;

seal means between said hanger body and said suspension means; and

testing means on said hanger body for testing the integrity of said seal means and the packer;

said locking means including a sleeve member reciprocally mounted within said hanger body and responsive to the longitudinal movement of a well too] whereby said sleeve member has at least one position in which it locks said securement means in said secured position.

10. A well pipe hanger assembly for suspending at least one string of pipe having a packer in a well comprising:

a hanger body having at least one axial bore therethorugh;

support means for supporting said hanger body within such well;

securement means for securing said hanger body within such well;

locking means for locking said securement means in a secured position;

actuator means for moving said locking means to its locking position;

alignment means for aligning the hanger assembly;

suspension means on said hanger body for suspending the string of pipe therefrom;

seal means between said hanger body and said suspension means; and testing means on said hanger body for testing the integrity of said seal means and the packer;

supporting structure within the well wherein said alignment means includes a first orientation means on the assembly cooperable with a second orientation means disposed on said supporting structure in a predetermined direction to position the assembly within the well in a predetermined angular orientation. relative thereto.

11. An underwater well apparatus for orienting and locking a well pipe hanger in a predetermined angular position relative to a reference member comprising:

hanger body means adapted to be supported within the well; orienting means associated with said hanger body means engaging the reference member to place said hanger body means in a predetermined angular position relative to the reference member;

lock means for securing said hanger body means within the well;

an actuator reciprocally mounted on said hanger body means and operatively connected to a handling string extending to the surface; and

a sleeve member reciprocally mounted within said hanger body means and responsive to the reciprocal movement of said actuator, said sleeve member being engageable with-said lock means whereby upon the longitudinal movement of said sleeve member said lock means secures said hanger body means within the well.

12. A well apparatus according to claim 11 wherein said actuator prevents the rotation of said member relative to said hanger body means.

13. The apparatus of claim 11 further including holding means for holding said sleeve member in position in the well, said holding means being responsive to the axial rotation of said actuator, whereby upon the axial rotation of said actuator said hold down means secures said sleeve member within the well.

14. An underwater well apparatus comprising:

a well pipe hanger assembly;

a well tool having a generally cylindrical body with at least one axial bore therethrough, said body having upper and lower ends with said lower end adapted for cooperatively engaging said well pipe hanger assembly;

at least one nipple means rotatably extending through a bore in said body;

means for releasably connecting said nipple means to a pipe coupling mounted in said pipe hanger assembly; and

means associated with said assembly to secure said pipe coupling within said assembly upon rotation of said nipple means. 15. A method of underwater testing of seals of a tubing hanger and of underwater testing a packer packing around all tubing strings suspended by the tubing hanger, comprising:

applying fluid pressure through a first testing string suspended within a conduit extending to the surface and in fluid tight communication with a tubing string suspended to an area below the hanger;

monitoring the conduit above the hanger for leaks in the seals;

setting said packer to pack off the area between all the tubing strings and the well;

applying fluid pressure through the first testing string;

and

monitoring a second testing string in fluid communication through and below said hanger and above said packer.

16. A method of testing a downhole packer comprising the steps of:

setting a downhole packer to pack around a short and a long tubing string suspended by a hanger within the well;

installing a back pressure valve in the long tubing string; pressurizing a first testing string in fluid tight communication with the short tubing string thereby applying a pressure below the downhole packer;

passing any leakage of the downhole packer at the area below the hanger and above the packer through the tubing hanger and into a second testing string; and

monitoring the second testing string to detect any leaks.

17. A well apparatus for a well having a tubular member extending into the well, comprising:

a well pipe hanger for suspending at least one pipe string within the tubular member;

sealing means for sealing between the tubular member, said well pipe hanger and said pipe string; packer means for packing between said pipe string and the tubular member; and

testing means on said well pipe hanger extending to the surface and lowered with said hanger into the well for testing said sealing means and said packer means individually.

18. An underwater well apparatus for suspending pipe string having a packer within a well comprising:

a well pipe hanger suspending at least one pipe string;

a well tool having at least one bore therethrough and at least two testing strings extending to the surface;

one of said testing strings passing through said bore and being releasably connected to said hanger, said one of said testing strings being in fluid tight communication with said pipe string; and

means providing communication between said second testing string and the space below said hanger and above the packer.

19. An underwater well apparatus for suspending pipe string within a well comprising:

a well pipe hanger suspending at least a short and a long well pipe string and having atleast two axial bores therethrough;

a running and testing tool having passage means therein for communicating with each well pipe string, said tool including a first and a second handling string each passing through one of said axial bores;

said first and second handling strings having lower ends releasably connected to said hanger;

said first handling string being in fluid tight communication with said short well pipe string;

said second handling string being in fluid tight communication with said long well pipe string;

means providing communication between the space below said hanger and said second handling string.

20. A well apparatus for completing a well having an outer casing, an inner casing and tubing suspended within the well by hangers comprising:

a tubular adapter lowerable to and engageable with one of such casing hangers in fluidtight connection therewith; said adapter being provided with packoff means engageable with a wall of the casing hanger to which said adapter is attached and engageable with such other casing hanger to prevent fluid passage through the annulus created by such outer casing and inner casing;

flow control means for controlling the fluid flow from such tubing;

nipple means for fluid tight communication between said flow control means and such tubing;

orientation means for aligning said nipple means with such tubing;

connection means for releasably connecting said flow control means and said adapter; and

seal means for sealing said flow control means and said adapter.

21. A well apparatus for completing a well having an outer casing, an inner casing and tubing suspended within the well by hangers, the hanger for said tubing having seals thereon for sealing therearound, comprismg:

a tubular adapter lowerable to and engageable with one of such casing hangers in fluidtight connection therewith; said adapter being provided with packoff means engageable with a wall of the casing hanger to which said adapter is attached and with the other casing hanger to prevent fluid passage through the annulus created by such outer casing and inner casing; and

a running testing tool having releasable connection means for lowering said adapter into the well and connecting said adapter to such one of such casing hangers and testing means for testing of said tubing hanger seals and said packoff means.

22. A well apparatus according to claim 21 wherein said packoff means includes seal means for sealingly engaging such casing hangers and seal retainer means attached to said adapter by bearing means permitting said adapter to be rotated to compress said seal means while said seal means remains stationary.

23. A well apparatus according to claim 21 and including a running string attached to said tool, and means providing communication between the running tool and the annulus between the casing hangers above the seal means.

24. A well apparatus according to claim 21 further including lock means for locking said adapter in position after said seal is compressed thereby preventing rotation of said adapter in either direction with respect to said casing hangers, and actuator means on said tool for actuating said lock means.

25. A well apparatus according to claim 21 further including a connection means between said adapter and said one of such casing hangers fully engageable on less than 360 rotation of said adapter relative to said one of such casing hangers.

26. A well apparatus according to claim 25 wherein said connection means is provided with locking means engageable with said adapter and said one of such casing hangers to prevent disengagement of said connection means.

27. A well apparatus according to claim 21 wherein such one of such casing hangers is the outer casing hanger and wherein said connection means comprises:

a plurality of circumferentially spaced groupings of teeth having no lead angle disposed on the inner wall of said outer casing hanger and on the circumference of said adapter;

said adapter teeth being insertable within said outer casing hanger;

said outer casing hanger and said adapter being connectable upon the rotation of said adapter and releasable upon a rotation of said adapter in the opposite direction; and

at least one stop on said adapter engageable with said outer casing hanger to limit the rotation of said adapter to less than one revolution.

28. A well apparatus comprising:

a well pipe hanger assembly;

running means attachable to said well pipe hanger assembly for running saidassembly into a wellhead element;

at least one string of pipe suspended from said assembly;

packer means for packing around said pipe;

first seal means established between said assembly and the wellhead element;

second seal means established between said assembly and said pipe;

first testing means for testing the integrity of said first seal means and said second seal means;

second testing means for testing the integrity of said packer by monitoring said running means, said well apparatus facilitating the testing of said packer means, said first seal means, and said second seal means with only one trip into the well.

29. A well apparatus according to claim 28 wherein said second testing means includes means for applying pressure below said packer and means passing any leakage above the packer to said running means to detect any leaks.

30. A well apparatus for a well having a tubular member extending into the well and including at least one pipe string comprising:

packer means for packing between the pipe string and the tubular member;

a well pipe hanger for suspending the pipe string within the tubular member, said well pipe hanger including a bore for each pipe string suspended by said well pipe hanger within the well and another passage through said well pipe hanger for transmitting any leakage of said packer means;

sealing means for sealing between the tubular member, said well pipe hanger and the pipe string; and

testing means for testing said sealing means and said packer means individually.

31. A well apparatus for orientating and locking a well pipe hanger in a predetermined angular position relative to said reference member comprising:

hanger body means adapted to be supported within the well;

said securement means prevents the rotation of said member relative to said hanger body means. 

1. A method of suspending at least one string of pipe in a well with only one trip into the well comprising the following steps: running a well pipe hanger assembly which suspends the pipe string into the well on at least two handling strings; aligning the well pipe hanger assembly in a predetermined position within the well; landing the well pipe hanger assembly within the well; locking down the well pipe hanger assembly within the well; testing the seals in the well pipe hanger assembly by pressurizing the handling strings; testing the integrity of the packer in the pipe string by monitoring one of the handling strings; and removing the handling strings.
 2. An underwater well pipe hanger assembly for suspending at least one string of pipe having a packer in a well comprising: a hanger body; support means for supporting said hanger body within the well; securement means for securing said hanger body within the well; locking means for locking said securement means in a secured position; actuator means for moving said locking means to its locking position; alignment means for aligning said hanger assembly; suspension means on said hanger body for suspending the string of pipe therefrom; seal means between said hanger body and said suspension means; and testing means on said hanger body extending to the surface and lowered with said hanger body into the well for testing the integrity of said seal means and the packer.
 3. A pipe hanger assembly according to claim 2 wherein said hanger body is adapted for releasable connection to a well tool, and wherein said actuator means includes means for releasably and rotatably connecting said actuator means to the well tool, and wherein said locking means is movable into its locking position by longitudinal force applied to said actuator means by the well tool.
 4. A pipe hanger assembly according to claim 3 wherein rotation of said well tool releases its connection to said hanger body.
 5. A pipe hanger assembly according to claim 2 and including a reference member disposed in a predetermined direction with the well wherein said alignment means comprises an alignment key protruding from said assembly, said alignment key cooperating with said reference member to cause rotation of said hanger assembly until said assembly is aligned within the well in a predetermined direction, and then to preclude further rotation of said alignment key and said hanger body.
 6. A pipe hanger assembly according to claim 5 wherein said reference member has a helically generated upwardly facing surface cooperable with said alignment key causing said hanger assembly to become aligned within the well in a predetermined direction.
 7. An assembly according to claim 2 wherein said testing means includes at least two conduits extending to the surface; one of said conduits being in fluid tight communication with the pipe string; and means providing communication between the space below said hanger body and said second conduit.
 8. An assembly according to claim 7 wherein said conduits lower said hanger body into the well.
 9. A well pipe hanger assembly for suspending at least one string of pipe having a packer in a well comprising: a hanger body having at least one axial bore therethrough; support means for supporting said hanger body within such well; securement means for securing said hanger body within such well; locking means for locking said securement means in a secured position; actuator means for moving said locking means to its locking position; alignment means for aligning the hanger assembly; suspension means on said hanger body for suspending the string of pipe therefrom; seal means between said hanger body and said suspension means; and testing means on said hanger body for testing the integrity of said seal means and the packer; said locking means including a sleeve member reciprocally mounted within said hanger body and responsive to the longitudinal movement of a well tool whereby said sleeve member has at least one position in which it locks said securement means in said secured position.
 10. A well pipe hanger assembly for suspending at least one string of pipe having a packer in a well comprising: a hanger body having at least one axial bore therethorugh; support means for supporting said hanger body within such well; securement means for securing said hanger body within such well; locking means for locking said securement means in a secured position; actuator means for moving said locking means to its locking position; alignment means for aligning the hanger assembly; suspension means on said hanger body for suspending the string of pipe therefrom; seal means between said hanger body and said suspension means; and testing means on said hanger body for testing the integrity of said seal means and the packer; supporting structure within the well wherein said alignment means includes a first orientation means on the assembly cooperable with a second orientation means disposed on said supporting structure in a predetermined direction to position the assembly within the well in a predetermined angular orientation relative thereto.
 11. An underwater well apparatus for orienting and locking a well pipe hanger in a predetermined angular position relative to a reference member comprising: hanger body means adapted to be supported within the well; orienting means associated with said hanger body means engaging the reference member to place said hanger body means in a predetermined angular position relative to the reference member; lock means for securing said hanger body means within the well; an actuator reciprocally mounted on said hanger body means and operatively connected to a handling string extending to the surface; and a sleeve member reciprocally mounted within said hanger body means and responsive to the reciprocal movement of said actuator, said sleeve member being engageable with said lock means whereby upon the longitudinal movement of said sleeve member said lock means secures said hanger body means within the well.
 12. A well apparatus according to claim 11 wherein said actuator prevents the rotation of said member relative to said hanger body means.
 13. The apparatus of claim 11 further including holding means for holding said sleeve member in position in the well, said holding means being responsive to the axial rotation of said actuator, whereby upon the axial rotation of said actuator said hold down means secures said sleeve member within the well.
 14. An underwater well apparatus comprising: a well pipe hanger assembly; a well tool having a generally cylindrical body with at least one axial bore therethrough, said body having upper and lower ends with said lower end adapted for cooperatively engaging said well pipe hanger assembly; at least one nipple means rotatably extending through a bore in said body; means for releasably connecting said nipple means to a pipe coupling mounted in said pipe hanger assembly; and means associated with said assembly to secure said pipe coupling within said assembly upon rotation of said nipple means.
 15. A method of underwater testing of seals of a tubing hanger and of underwater testing a packer packing around all tubing strings suspended by the tubing hanger, comprising: applying fluid pressure through a first testing string suspended within a conduit extending to the surface and in fluid tight communication with a tubing string suspended to an area below the hanger; monitoring the conduit above the hanger for leaks in the seals; setting said packer to pack off the area between all the tubing strings and the well; applying fluid pressure through the first testing string; and monitoring a second testing string in fluid communication through and below said hanger and above said packer.
 16. A method of testing a downhole packer comprising the steps of: setting a downhole packer to pack around a short and a long tubing string suspended by a hanger within the well; installing a back pressure valve in the long tubing string; pressurizing a first testing string in fluid tight communication with the short tubing string thereby applying a pressure below the downhole packer; passing any leakage of the downhole packer at the area below the hanger and above the packer through the tubing hanger and into a second testing string; and monitoring the second testing string to detect any leaks.
 17. A well apparatus for a well having a tubular member extending into the well, comprising: a well pipe hanger for suspending at least one pipe string within the tubular member; sealing means for sealing between thE tubular member, said well pipe hanger and said pipe string; packer means for packing between said pipe string and the tubular member; and testing means on said well pipe hanger extending to the surface and lowered with said hanger into the well for testing said sealing means and said packer means individually.
 18. An underwater well apparatus for suspending pipe string having a packer within a well comprising: a well pipe hanger suspending at least one pipe string; a well tool having at least one bore therethrough and at least two testing strings extending to the surface; one of said testing strings passing through said bore and being releasably connected to said hanger, said one of said testing strings being in fluid tight communication with said pipe string; and means providing communication between said second testing string and the space below said hanger and above the packer.
 19. An underwater well apparatus for suspending pipe string within a well comprising: a well pipe hanger suspending at least a short and a long well pipe string and having at least two axial bores therethrough; a running and testing tool having passage means therein for communicating with each well pipe string, said tool including a first and a second handling string each passing through one of said axial bores; said first and second handling strings having lower ends releasably connected to said hanger; said first handling string being in fluid tight communication with said short well pipe string; said second handling string being in fluid tight communication with said long well pipe string; means providing communication between the space below said hanger and said second handling string.
 20. A well apparatus for completing a well having an outer casing, an inner casing and tubing suspended within the well by hangers comprising: a tubular adapter lowerable to and engageable with one of such casing hangers in fluidtight connection therewith; said adapter being provided with packoff means engageable with a wall of the casing hanger to which said adapter is attached and engageable with such other casing hanger to prevent fluid passage through the annulus created by such outer casing and inner casing; flow control means for controlling the fluid flow from such tubing; nipple means for fluid tight communication between said flow control means and such tubing; orientation means for aligning said nipple means with such tubing; connection means for releasably connecting said flow control means and said adapter; and seal means for sealing said flow control means and said adapter.
 21. A well apparatus for completing a well having an outer casing, an inner casing and tubing suspended within the well by hangers, the hanger for said tubing having seals thereon for sealing therearound, comprising: a tubular adapter lowerable to and engageable with one of such casing hangers in fluidtight connection therewith; said adapter being provided with packoff means engageable with a wall of the casing hanger to which said adapter is attached and with the other casing hanger to prevent fluid passage through the annulus created by such outer casing and inner casing; and a running testing tool having releasable connection means for lowering said adapter into the well and connecting said adapter to such one of such casing hangers and testing means for testing of said tubing hanger seals and said packoff means.
 22. A well apparatus according to claim 21 wherein said packoff means includes seal means for sealingly engaging such casing hangers and seal retainer means attached to said adapter by bearing means permitting said adapter to be rotated to compress said seal means while said seal means remains stationary.
 23. A well apparatus according to claim 21 and including a running string attached to said tool, and means providing communication between the running tool and the annulus between the cAsing hangers above the seal means.
 24. A well apparatus according to claim 21 further including lock means for locking said adapter in position after said seal is compressed thereby preventing rotation of said adapter in either direction with respect to said casing hangers, and actuator means on said tool for actuating said lock means.
 25. A well apparatus according to claim 21 further including a connection means between said adapter and said one of such casing hangers fully engageable on less than 360* rotation of said adapter relative to said one of such casing hangers.
 26. A well apparatus according to claim 25 wherein said connection means is provided with locking means engageable with said adapter and said one of such casing hangers to prevent disengagement of said connection means.
 27. A well apparatus according to claim 21 wherein such one of such casing hangers is the outer casing hanger and wherein said connection means comprises: a plurality of circumferentially spaced groupings of teeth having no lead angle disposed on the inner wall of said outer casing hanger and on the circumference of said adapter; said adapter teeth being insertable within said outer casing hanger; said outer casing hanger and said adapter being connectable upon the rotation of said adapter and releasable upon a rotation of said adapter in the opposite direction; and at least one stop on said adapter engageable with said outer casing hanger to limit the rotation of said adapter to less than one revolution.
 28. A well apparatus comprising: a well pipe hanger assembly; running means attachable to said well pipe hanger assembly for running said assembly into a wellhead element; at least one string of pipe suspended from said assembly; packer means for packing around said pipe; first seal means established between said assembly and the wellhead element; second seal means established between said assembly and said pipe; first testing means for testing the integrity of said first seal means and said second seal means; second testing means for testing the integrity of said packer by monitoring said running means, said well apparatus facilitating the testing of said packer means, said first seal means, and said second seal means with only one trip into the well.
 29. A well apparatus according to claim 28 wherein said second testing means includes means for applying pressure below said packer and means passing any leakage above the packer to said running means to detect any leaks.
 30. A well apparatus for a well having a tubular member extending into the well and including at least one pipe string comprising: packer means for packing between the pipe string and the tubular member; a well pipe hanger for suspending the pipe string within the tubular member, said well pipe hanger including a bore for each pipe string suspended by said well pipe hanger within the well and another passage through said well pipe hanger for transmitting any leakage of said packer means; sealing means for sealing between the tubular member, said well pipe hanger and the pipe string; and testing means for testing said sealing means and said packer means individually.
 31. A well apparatus for orientating and locking a well pipe hanger in a predetermined angular position relative to said reference member comprising: hanger body means adapted to be supported within the well; orientating means associated with said hanger body means engaging the reference member to place said hanger body means in a predetermined angular position relative to the reference number; securement means for securing said hanger body means within the well, said securement means being movable into a locked position by longitudinal force applied to said securement means, said longitudinal force being applied from a position remote from said securement means and through a handling string operatively connected to said securEment means.
 32. A well apparatus according to claim 31 wherein said securement means prevents the rotation of said member relative to said hanger body means. 